1. Field of the Invention
The present invention relates to a hydraulic shock absorbing apparatus of a vehicle.
2. Description of the Related Art
For a hydraulic shock absorber of a vehicle, there is a structure in which a hydraulic shock absorber is provided in right and left sides of a wheel. As shown in Japanese Unexamined Utility Model Publication No. 64-41495, each of the shock absorbers has an expansion side damping force generating apparatus which is provided with two oil passages in a piston sliding within a cylinder. An expansion side damping valve generating an expansion side damping force in one oil passage is present, along with a compression side check valve easily opened at the time of compression and generating a slight compression side damping force in another oil passage. Each of the shock absorbers has a compression side damping force generating apparatus which is provided with two oil passages in a sub piston fixed to a bottom portion of the cylinder. A compression side damping valve generating a compression side damping force with respect to a working fluid in correspondence to a forward moving volume of a piston rod in one oil passage is present. An expansion check valve is also present and which is easily opened at the time of expansion and which generating a slight expansion side damping force in another oil passage.
In the conventional art, both of the hydraulic shock absorbers provided in both sides of the wheel have the expansion side damping force generating apparatus provided in the piston sliding within the cylinder, and the compression side damping force generating apparatus provided in the sub piston fixed to the bottom portion of the cylinder. Accordingly, the damping valve structure in each of the hydraulic shock absorbers is complex so as to increase the number of the parts, thereby making it difficult to reduce manufacturing cost.